Controlled heat exchanger system

Abstract

A system for transferring heat from a first (inner) surface through a second (outer) surface. The system includes at least two adjacent porous and thermally conductive layers between the first surface and the second surface. The innermost layer is characterized by a relatively high porosity and the outermost layer is characterized by a relatively low porosity. The innermost layer houses a fluid coolant. The pores of the innermost and outermost layers are coupled, permitting coolant flow therebetween. A vapor chamber is positioned between the outer surface and an outer member. A controller is adapted to control the vapor pressure in the vapor chamber whereby the coolant has a liquid vapor phase transition in the outermost layer.

I claim: 
     
       1. A system for transferring heat from a first surface through a second surface, said second surface being characterized by substantially uniform thermal envelope, comprising: an inner porous layer adjacent to said first surface, said inner layer being characterized by relatively high porosity and thermal conductivity, and being adapted to house coolant,   an outer porous layer between said inner layer and said second surface, said outer layer being characterized by a relatively low porosity and relatively high thermal conductivity, wherein said outer layer is thermally coupled to said inner layer and the pores of said outer layer are coupled to the pores of said inner layer permitting coolant flow therebetween, wherein the pores of one of said porous layers are filled with a material whereby coolant flow is prevented between inner and outer pores, said material characterized by a predetermined melting point whereby said material melts and said coolant flow is permitted when said first surface reaches a predetermined temperature,   a vapor chamber between said second surface and an outer member,   means for selectively controlling the vapor pressure in said vapor chamber whereby said coolant has a liquid vapor phase transition within said outer layer.